[Nut-upsuser] NUT and ESXi hypervisors (for example)

[Jim Klimov]

> It requires a UPS unit capable of restarting when power eventually
returns.

Can't say much about particular vendors, models and firmware/hardware
versions, but generally note that some UPSes (more so "enterprise-ish"
ones) would insist on powering up the load only after charging to a safe
level, either 100% or whatever threshold is deemed/configured sufficient to
safely shut down the load if another outage occurs. So if your earlier
outage tried to keep the servers afloat as long as possible and drained the
battery, some hours can pass after the outage ends before such UPS would
auto-start them. Usually this behavior can be overridden by the physical
power button, or by networked (Web, SNMP, Telnet/SSH...) interfaces of the
UPS where available and accessible.

I did encounter Eaton UPSes from the enterprise line-up with NetXML
protocol which are quite smart, with UPS-issued network alerts to
subscribed devices (so the NUT netxml-ups driver can be one of those, with
respective settings). Even if powered on manually "prematurely", they
regularly sent the alert about critical battery state (not yet charged
enough to be safe), so soon after the server and NUT started, an alert was
received and FSD (Forced Shut Down) was initiated. It was crucial during
maintenance and development around this to log in quickly after boot and
disable NUT (or disable its autostart temporarily, when planned
development/troubleshooting happened).

On a personal level, when you know the power situation is okay, it is
annoying. On the business level, where corrupted data can cost more than an
extra duration of an outage (go get diesel gensets otherwise) this is a
fair trade-off especially if the boxes are not monitored 24/7 by humans who
know better.

Jim Klimov



On Wed, Jul 31, 2024 at 10:12 AM Harlan Stenn via Nut-upsuser <
nut-upsuser at alioth-lists.debian.net> wrote:

> Thanks for the response, Roger.
>
> On 7/31/2024 12:19 AM, Roger Price wrote:
> > On Tue, 30 Jul 2024, Harlan Stenn via Nut-upsuser wrote:
> >
> >> I've got a client who lives in an area where there are now frequent
> >> power outages that last for several hours at a time.
> >
> > I live in an area with frequent power outages, so I use a nut
> > configuration [1] which shuts down the system using a timer rather than
> > waiting for LB status.
>
> That's what we'd like to do.
>
> > Important: It requires a UPS unit capable of restarting when power
> > eventually returns.  Eaton seem to have removed this capability from the
> > recent Ellipse ECO products maybe to force customers to the Ellipse PRO
> > line.
>
> Today, we're using APC SMT2200 units.  I'll have to look to see if this
> is supported there or not.
>
> H
>
> > Roger
> >
> > [1] The configuration is described in chapter 7 "Workstation with timed
> > shutdown", of the Configuration Examples
> > https://rogerprice.org/NUT/ConfigExamples.A5.pdf
> >
> >
> > _______________________________________________
> > Nut-upsuser mailing list
> > Nut-upsuser at alioth-lists.debian.net
> > https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/nut-upsuser
> >
>
> _______________________________________________
> Nut-upsuser mailing list
> Nut-upsuser at alioth-lists.debian.net
> https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/nut-upsuser
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://alioth-lists.debian.net/pipermail/nut-upsuser/attachments/20240731/82cf675f/attachment.htm>